1. Field of the Invention
The present invention relates to a thermal-type inkjet recording apparatus and an abnormality detection method of a liquid discharge head.
2. Description of the Related Art
An inkjet recording apparatus includes a thermal-type inkjet recording apparatus in which an inkjet recording head manufactured with a technology such as a chemical vapor deposition (CVD) method heats ink and discharges the ink (discussed in Japanese Patent Application Laid-Open No. 9-57973).
FIG. 11 illustrates a cross-sectional view of a configuration of an inkjet recording head used for a conventional thermal-type inkjet recording apparatus.
In an inkjet recording head 500 illustrated in FIG. 11, a thermal accumulation layer 502, a lower protection film 503, a heat generation resistor 504, a wiring 505, an upper protection film 506, and a nozzle member 507 are laminated on a substrate 501. A supply port 508 to which ink flows is formed in the inkjet recording head 500. The lower protection film 503 and the upper protection film 506 come into contact with the supply port 508.
In the inkjet recording head 500, a voltage is applied to the heat generation resistor 504 via the wiring 505. Then, the heat generation resistor 504 is heated, and the ink flowing from the supply port 508 is also heated. The ink is discharged from a discharge port 509 formed in the nozzle member 507 in air bubbles generated by the heating. In the inkjet recording head 500, the upper protection film 506 and the lower protection film 503 are formed, thereby protecting the heat generation resistor 504 and the wiring 505 from the ink.
In the inkjet recording head 500, the upper protection film 506 and the lower protection film 503 generally contain a silicon compound. Therefore, depending on the kind of ink, the upper protection film 506 and the lower protection film 503 can be temporally corroded from a contact portion with the supply port 508.
FIG. 12 illustrates a cross-sectional view of a status in which the inkjet recording head 500 in FIG. 11 is corroded by ink. Referring to FIG. 12, the corrosion with the ink enhances a dissolution region (refer to a region C) of the upper protection film 506 and the lower protection film 503. Then, the ink enters the wiring 505. Then, there is a danger that the inkjet recording head 500 is not normally operated.